Siamese cable refers to a type of combination cable that makes it possible to run two types of wiring – typically for power and data transmission – to a given location through a single cable. Siamese cables offer cleaner and more organized installations, and are commonly used in video, surveillance camera and closed-circuit television (CCTV) applications for that very reason: equipment can be wired for power and signal without the installer having to use separate cables for each type of connection. So siamese cable makes CCTV camera installation easier. RG59U Siamese coaxial cables are great for distance.